1. Field of the Invention
The present invention relates to a wiring connection method for leading out wiring of an electric circuit inside an electronic apparatus to the outside, and more particularly to a wiring connection method and structure for a power wiring connection to which a large current is applied.
2. Description of the Related Art
FIG. 7 is an appearance view showing a wiring connection structure according to the related art for making wiring of an electronic apparatus to the outside. FIG. 8 is a cross-sectional view showing the wiring connection structure according to the related art for making the wiring of the electronic apparatus to the outside, taken along the line A–A′ in FIG. 7.
Generally, the wiring connection method and structure according to the related art for leading out the electric circuit wiring inside the electronic apparatus to the outside, particularly the power wiring connection method and structure in which a large current is applied is constructed so that a bus bar 4 and a connector pin 7 are insert molded in a housing 5 for the electronic apparatus and the bus bar 4 is connected via the soldered connector pin 7 to the outside, as shown in FIGS. 7 and 8.
As shown in FIGS. 7 and 8, in a wiring connection structure 70 according to the related art for leading out wiring in the electronic apparatus to the outside, the bus bar 4 and the connector pin 7 are insert molded in the case 5 molded of a resin material for the electric circuit. The bus bar 4 is made of a metal material such as copper useful to supply a large current. The connector pin 7 is made of metal material such as copper and formed in L shape to lead out the electric circuit wiring to the outside. An electric circuit substrate portion 1 having electronic parts packaged on a printed board 2 (referred to as a board 2) is mounted within the housing 5, in which the connector pin 7 and the bus bar 4, and the bus bar 4 and the land on the board 2 are soldered, respectively.
In this wiring connection, the wiring for the electric circuit substrate portion 1 composed of electric circuits including a control circuit is connected via the bus bar 4 and the connector pin 7 to a power supply wiring such as an external battery (connected to a connector 9a) and a load wiring (connected to a connector 9b) by means of a connector 8 for outside connection. Within this housing 5, the electric circuit substrate portion 1 is mounted and after wiring connection, a lid 6 molded of resin material is put on the housing 5, whereby the electronic apparatus is assembled.
The housing 5 is molded of resin material like a box, and has the bus bar 4 and the connector pin 7 insert molded. The electric circuit substrate portion 1 is mounted within the housing 5.
Projection ribs 5c and 5d are provided on the inner faces of a front frame portion and a rear frame portion for this housing 5, respectively. End portions 4c and 4d of the bus bar 4 are insert molded into the projection ribs 5c and 5d. The electric circuit substrate portion 1 is mounted on the upper faces 5e and 5f of the projection ribs 5c and 5d. 
A projection portion 5a having a concave portion, 5b with an opening at one end to insert the connector 8 for outside connection is provided on an outer surface of the front frame portion for the housing 5. The connector pin 7 is insert molded into a bottom wall 5h of this concave portion 5b. A rib 5g for being attached the lid 6 made of resin material to is molded on an upper face portion with an opening in the housing 5. The connector 8 for outside connection is inserted into the concave portion 5b of the projection portion 5a into which the connector pin 7 for this housing 5 is insert molded. The electric circuit wiring including a control circuit in the electric circuit substrate portion 1 mounted within the housing 5 is connected via the connector pin 7 to the power source supply wiring connector 9a for the external battery and the load wiring connector 9b by means of the connector 8 for outside connection.
The bus bar 4 has the terminals 4a, 4b formed by punching and bending a part of the bus bar 4 at positions spaced apart a predetermined distance from one end of the front face side toward the rear face side (e.g., a junction position with the connector pin 7, and a junction position with a land of the board 2), the terminals 4a and 4b being formed of a metal material such as copper like a plate. This bus bar 4 has the end portions 4c and 4d insert molded into the projection ribs 5c and 5d provided on the front frame portion and the rear frame portion of the housing 5, respectively. This bus bar 4 connects the power supply wiring via the connector pin 7 to the land on the board 2 by soldering the terminal 4a of the bus bar 4 with a junction portion 71 of the connector pin 7 and soldering the terminal 4b of the bus bar 4 with a junction portion 72 of the board 2, after the electric circuit substrate portion 1 is mounted within the housing 5.
In the above wiring connection method and structure for leading out the wiring inside the electronic apparatus to the outside, particularly the power wiring connection method and structure in which a large current is applied, it is required to solder the bus bar and the connector pin provided within the housing of the electronic apparatus and to solder the board and the bus bar. The soldering must be performed after the bus bar, the connector pin, and the board are accommodated within the housing, and takes a lot of trouble. Also, the connector is used for wiring connection, resulting in increase of costs.